Balancing the Rig
How many times have we seen some poor helmsman struggling along close hauled with the wheel hard over in one direction or another, trying to keep the yacht either on, or off, the wind! She is either trying to round up all the time, or fighting shy of the wind.
You can have the best trimmed sails and still have an unbalanced rig; and you will always feel it on the helm. In fact, the better you trim the sails, the more you will notice if the rig is unbalanced.
You might have excessive weather helm, where the yacht keeps trying to round up into the wind, and the helmsman has to fight the wheel or the tiller to keep her off the wind. Or you might have excessive lee helm, where the helmsman is struggling to keep her close to the wind.
And to make matters worse, you might have so much canvas up that the yacht is heeling hard, and the top of the mainsail is dumping precious wind to leeward, ruining the twist and causing the weather helm to increase sometimes to the point of broaching, and the knots to decrease alarmingly.
The basic aim of sail trimming is to get maximum lift from the sail, minimum heeling moment, and maximum forward movement. We also want to avoid lee helm, excessive weather helm, and over-powering the rig: balancing the rig properly is all about getting maximum forward movement.
Let's start by balancing the helm. What we want to achieve is a very slight weather helm. That way, the helmsman will be able to steer with a fingertip rather than hanging on like grim death, and the yacht will respond to each tiny movement of the wheel or tiller.
Too much weather helm happens when the mainsail overpowers the headsail, and turns the yacht into the wind. The helmsman has to steer constantly away from the wind, and with the rudder at 45 degrees from the direction of travel, it acts like a brake, slowing the yacht right down.
On a modern, beamy yacht it can be dangerous, because when the yacht heels sharply, the already over-pressed rudder cavitates like mad, losing all its grip, the helmsman loses control, and the yacht rounds sharply up into the wind, heeling violently.
The broach can be both sudden and vicious, and you end up with the yacht on its beam until sufficient wind is spilled from the sails. A bad broach can empty the fridge and the wine rack at the same time as letting rather too much sea water into the yacht.
You can stop this happening in an emergency by easing the main quickly, but you really want to prevent it in the first place. You can correct excessive weather helm either by rolling out more headsail (if you have a roller reefing system on the headsail, this is an easy way to balance the yacht), by flattening the mainsail with the out-haul and kicker so that she doesn't pull so much, or by putting a reef into the main and adjusting the headsail to match.
By doing that, you keep the rudder's angle of attack much more in line with the direction of the yacht, and she won't lose grip so badly when a gust comes.
Lee helm happens when the headsail is overpowering the main, and pulling the yacht off the wind. It's miserable, both for the helmsman, and for the feel of the yacht. Again, the rudder will be at a constant 45 degrees to the direction of travel as the helmsman keeps trying to get her near the wind, and acting like a brake.
You can correct it with a roller-reefed headsail simply by rolling a bit of the headsail away and then trimming the sails again. Whatever you do, try not to sail with any lee helm. The helmsman will be exhausted in a matter of hours, the passage will be long and slow, and you could well burn the motor out of your autopilot on a long passage.
A solid, long-keeled yacht can be made to sail a straight course without anyone at all on the helm simply by adjusting the balance of the rig. It's a good game to play if you have the time, just to sharpen your balancing skills. A wing keeled yacht won't do this, but it will sail better if the balance is right.
And finally, don't let the yacht heel excessively. I know it looks good in photographs, and lots of people love the 'gunnels under' feeling, but it's not the most efficient way to sail.
The wind blows slightly stronger at higher levels, and you want to keep the mast presenting the sails at the right degree of twist. Keeping her on her feet as far as possible is about not overpowering the yacht; it's about reefing when you need to.
She will sail faster, better, and point higher if she isn't being made to heel excessively. Reefing should be practised and practised until it's like changing gear on a car: done almost without thinking.
One final hint. Sometimes, when close reached and the waves are high enough to cause the yacht to slam, you will notice the yacht slow down each time she hits a wave. If this happens, sail a few degrees further off the wind, and ease the main traveller outwards a bit. You'll find she sails more upright, she will go faster, and the waves won't slow her down so much.
The aim is to get maximum lift, minimum heel and maximum forward movement. Trim correctly, balance the rig, and don't over-power her. You'll be popular with the crew, and will probably get there a lot quicker.
And remember; not all yachts will balance well. Most can be trimmed to sail like gliders, a few will only sail like pigs. There isn't much you can do about a bad design except try not to sail in one again.
Copyright © Richard Thomas 2007. All rights reserved
